21800041 has 4 divisors (see below), whose sum is σ = 21946500. Its totient is φ = 21653584.

The previous prime is 21800039. The next prime is 21800047. The reversal of 21800041 is 14000812.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9126441 + 12673600 = 3021^2 + 3560^2 .

It is a cyclic number.

It is not a de Polignac number, because 21800041 - 2¹ = 21800039 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21799988 and 21800024.

It is not an unprimeable number, because it can be changed into a prime (21800047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73006 + ... + 73303.

It is an arithmetic number, because the mean of its divisors is an integer number (5486625).

Almost surely, 2^21800041 is an apocalyptic number.

It is an amenable number.

21800041 is a deficient number, since it is larger than the sum of its proper divisors (146459).

21800041 is a wasteful number, since it uses less digits than its factorization.

21800041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146458.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 21800041 is about 4669.0514025870. The cubic root of 21800041 is about 279.3524192537.

Adding to 21800041 its reverse (14000812), we get a palindrome (35800853).

It can be divided in two parts, 21 and 800041, that multiplied together give a palindrome (16800861).

The spelling of 21800041 in words is "twenty-one million, eight hundred thousand, forty-one".